As projects end and operations begin, we argue that transition involves boundary-spanning work to ensure continuity across changing forms of organizing. A study of transition in the London megaproject ecology (Heathrow Terminal 5, London 2012 Olympics, and Crossrail) is used to build new theoretical insight into how transition is accomplished. We find that multiple temporalities meet and disjunctures emerge, with stability to close projects sought as interorganizational futures shift. Our work extends the research on temporal boundary spanning, to articulate how disjunctures and shifts are managed, and continuity is enhanced, through the use of artifacts, procedures, soft landings, and tests.